package day9;

import org.junit.Test;

public class TestStringBuilder {
    @Test
    public void test01() {
        StringBuilder sb = new StringBuilder(0123);
        sb.append("_abc");
        System.out.println(sb);
        sb.reverse();
        System.out.println(sb);
        sb.delete(0, 2);
        System.out.println(sb);
    }

    @Test
    public void addContentString() {
        String a="";
        for(int i=0;i<10000;i++){
            a+="A";

        }
    }
    @Test
    public void addContentStringBuilder() {
        StringBuilder sb=new StringBuilder();
        for(int i=0;i<10000;i++){
            sb.append("A");
        }
    }
    }

